Simplify the following expression: $\sqrt{250}+\sqrt{160}-\sqrt{40}$
First, try to factor any perfect squares out of the radicals. $= \sqrt{250}+\sqrt{160}-\sqrt{40}$ $= \sqrt{25 \cdot 10}+\sqrt{16 \cdot 10}-\sqrt{4 \cdot 10}$ Separate the radicals and simplify. $= \sqrt{25} \cdot \sqrt{10}+\sqrt{16} \cdot \sqrt{10}-\sqrt{4} \cdot \sqrt{10}$ $= 5\sqrt{10}+4\sqrt{10}-2\sqrt{10}$ Finally, simplify by combining the terms. $= ( 5 + 4 - 2 )\sqrt{10} = 7\sqrt{10}$